This text was adapted by The Saylor Foundation under a Creative Commons Attribution-NonCommercial-ShareAlike 0 License without attribution as requested by the work’s original creator or licensee. Preface

7.4 Explaining Drug Use



LEARNING OBJECTIVES

1. 
   Understand the possible biological origins of drug addiction.
   
2. 
   Explain why longitudinal research on personality traits and drug use is important.
   
3. 
   Outline the aspects of the social environment that may influence drug use.
   

To know how to reduce drug use, we must first know what explains it. The major explanations for drug use come from the fields of biology, psychology, and sociology.

Biological Explanations

In looking at drug use, the field of biology focuses on two related major questions. First, how and why do drugs affect a person’s behavior, mood, perception, and other qualities? Second, what biological factors explain why some people are more likely than others to use drugs?

Regarding the first question, the field of biology has an excellent understanding of how drugs work. The details of this understanding are beyond the scope of this chapter, but they involve how drugs affect areas in the brain and the neurotransmitters that cause a particular drug’s effects. For example, cocaine produces euphoria and other positive emotions in part because it first produces an accumulation of dopamine, a neurotransmitter linked to feelings of pleasure and enjoyment.

Regarding the second question, biological research is more speculative, but it assumes that some people are particularly vulnerable to the effects of drugs. These people are more likely to experience very intense effects and to become physiologically and/or psychologically addicted to a particular drug. To the extent this process occurs, the people in question are assumed to have a biological predisposition for drug addiction that is thought to be a genetic predisposition.

Most research on genetic predisposition has focused on alcohol and alcoholism (Hanson et al., 2012). ^[1] Studies of twins find that identical twins are more likely than fraternal twins (who are not genetically identical) to both have alcohol problems or not to have them. In addition, studies of children of alcoholic parents who are adopted by nonalcoholic parents find that these children are more likely than those born to nonalcoholic parents to develop alcohol problems themselves. Although a genetic predisposition for alcoholism might exist for reasons not yet well understood, there is not enough similar research on other types of drug addiction to assume that a genetic predisposition exists for these types. Many nonbiological factors also explain the use of, and addiction to, alcohol and other drugs. We now turn to these factors.